A.

      B.

Figure 1. Stem density distributions by cycle in Petersburg National Battlefield (PETE). Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Note that cycle 5 is only partially complete. Figure A shows regeneration densities by size class. Figure B shows tree density by diameter at breast height (DBH) increments. Error bars are 95% bootstrapped confidence intervals to account for non-normal error. An asterisk denotes a linear DBH distribution that is indicative of long-term recruitment failure.



Figure 2. Regeneration Debt status for the most recent 4-year census (2021 – 2023) in Petersburg National Battlefield (PETE). Flat Tree Diam. Dist. stands for Flat Tree Diameter Distribution. If TRUE, the density of small trees is lower than expected due to chronic regeneration failure. Sapling/Seedling Composition is the % of total stems composed of native canopy-forming species. Sorenson is a measure of how closely the regen. layer matches canopy composition. For more details on metric calculations, thresholds and assessment of status, see Miller et al. 2023.


Figure 3. Deer browse impacts by cycle in Petersburg National Battlefield (PETE). Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Note that cycle 5 is only partially complete.


Figure 4. Loess smoothed changes in stem density for seedlings (A) and saplings (B) by species group and sample year in Petersburg National Battlefield. Specified loess span approximated a linear trend between consecutive sample events per panel.



Figure 5. Loess smoothed changes in tree stem density (A) and basal area (B) by species group and sample year in Petersburg National Battlefield. Specified loess span approximated a linear trend between consecutive sample events per panel.



Figure 6. Loess smoothed changes in invasive plant percent cover by guild and sample year in Petersburg National Battlefield. Specified loess span approximated a linear trend between consecutive sample events per panel.



Table 1. Average plot-level seedling and sapling stem densities (stems per m2) and stocking index (at the 2m radius scale) by cycle. Only native, canopy-forming species are included. Note that Fraxinus spp. (ash species) are no longer considered canopy-forming species. Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Plots are sampled in 4-year rotations, with a quarter of the plots sampled each year (i.e. a panel). The stocking index quantifies whether current regeneration densities are sufficient to restock a forest canopy. The index is a weighted sum of seedling and sapling densities where larger seedling size classes get higher weights. Cells highlighted in green are plots that meet the minimum management target of 0.25 seedlings/m2 and 0.14 saplings/m2 or have a stocking index >100. These are the same thresholds used in Figure 2 and are described in Miller et al. 2023. Note that cycle 5 is only partially complete.

table output
Seedlings per sq.m
Saplings per sq.m
Stocking Index
Plot Panel Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5
21 1 0.17 0.00 0.00 0.00 0.08 0.07 0.04 0.02 0.02 0.02 9.55 7.41 0.00 0.00 1.01
22 1 0.25 0.00 0.08 0.08 0.33 0.02 0.02 0.02 0.02 0.02 5.28 0.00 1.01 2.14 5.28
23 1 0.75 0.75 0.33 0.17 0.50 0.02 0.01 0.01 0.00 0.00 32.42 12.57 5.28 3.14 7.29
24 1 0.08 0.08 0.17 0.08 0.08 0.11 0.06 0.04 0.04 0.04 8.42 1.01 9.55 8.42 15.83
25 1 0.33 0.08 0.17 0.17 0.33 0.08 0.07 0.06 0.05 0.04 34.81 16.96 4.15 4.15 24.13
26 1 0.00 0.17 0.08 0.25 0.33 0.06 0.04 0.04 0.02 0.02 14.83 2.14 2.14 3.14 6.28
27 1 0.00 0.00 0.00 0.00 0.08 0.06 0.06 0.05 0.05 0.05 0.00 0.00 0.00 0.00 1.01
65 1 1.17 0.17 0.00 0.00 0.00 0.08 0.08 0.06 0.06 0.07 24.13 3.14 0.00 0.00 7.41
66 1 1.50 2.75 3.83 4.33 4.50 0.18 0.15 0.14 0.12 0.08 80.17 84.19 68.24 88.22 75.52
67 1 0.75 0.58 0.92 0.25 0.58 0.12 0.12 0.08 0.02 0.02 50.64 55.92 44.23 17.97 18.98
68 1 3.08 2.17 2.67 1.75 1.75 0.33 0.24 0.20 0.13 0.08 86.21 158.34 148.79 86.96 40.84
69 1 0.25 0.25 0.08 0.00 0.08 0.48 0.42 0.29 0.19 0.13 115.36 101.54 60.32 44.48 30.66
70 1 0.08 0.00 0.00 0.08 0.00 0.37 0.35 0.25 0.17 0.09 38.08 37.07 29.66 23.25 7.41
103 2 0.25 0.42 0.08 0.08 - 0.40 0.25 0.19 0.11 - 34.81 91.23 8.42 2.14 -
104 2 0.33 0.75 0.42 0.67 - 0.46 0.37 0.32 0.28 - 123.78 170.40 181.71 189.88 -
105 2 0.50 1.17 1.00 0.83 - 0.37 0.25 0.21 0.15 - 166.63 86.58 88.47 52.78 -
109 2 0.17 0.42 0.25 0.08 - 0.15 0.14 0.13 0.12 - 60.07 35.94 27.52 15.83 -
110 2 0.17 0.17 0.50 0.08 - 0.14 0.15 0.14 0.11 - 37.82 18.98 25.26 2.14 -
111 2 0.58 0.33 0.25 0.58 - 0.14 0.11 0.12 0.12 - 69.74 42.22 34.81 68.49 -
135 2 0.42 0.50 0.17 0.83 - 0.15 0.14 0.11 0.07 - 29.53 22.12 17.97 11.56 -
136 2 5.75 2.58 1.67 0.50 - 0.00 0.00 0.00 0.00 - 116.24 48.13 51.27 10.43 -
137 2 0.00 0.17 0.83 0.50 - 0.06 0.06 0.05 0.02 - 0.00 3.14 10.43 6.28 -
138 2 0.08 0.17 1.00 2.00 - 0.08 0.06 0.05 0.05 - 1.01 2.14 14.70 30.41 -
139 2 0.33 0.33 0.25 0.67 - 0.22 0.21 0.21 0.17 - 84.45 110.46 88.47 144.76 -
140 2 0.00 0.00 0.17 0.42 - 0.05 0.05 0.04 0.04 - 0.00 0.00 2.14 5.28 -
141 2 0.00 0.00 0.17 0.83 - 0.00 0.00 0.00 0.00 - 0.00 0.00 2.14 10.43 -
172 3 1.25 1.33 1.08 1.00 - 0.33 0.26 0.26 0.22 - 159.97 186.99 151.42 115.61 -
186 3 0.17 0.00 0.08 0.00 - 0.07 0.06 0.06 0.05 - 2.14 0.00 1.01 0.00 -
188 3 0.67 0.83 0.42 0.42 - 0.19 0.17 0.15 0.14 - 76.91 96.64 81.93 30.66 -
189 3 0.33 0.42 0.58 0.92 - 0.08 0.05 0.02 0.02 - 12.69 12.69 7.29 11.56 -


Table 1 (cont.). Average plot-level seedling and sapling stem densities (stems per m2) and stocking index (at the 2m radius scale) by cycle. Only native, canopy-forming species are included. Note that Fraxinus spp. (ash species) are no longer considered canopy-forming species. Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Plots are sampled in 4-year rotations, with a quarter of the plots sampled each year (i.e. a panel). The stocking index quantifies whether current regeneration densities are sufficient to restock a forest canopy. The index is a weighted sum of seedling and sapling densities where larger seedling size classes get higher weights. Cells highlighted in green are plots that meet the minimum management target of 0.25 seedlings/m2 and 0.14 saplings/m2 or have a stocking index >100. These are the same thresholds used in Figure 2 and are described in Miller et al. 2023. Note that cycle 5 is only partially complete.

table output
Seedlings per sq.m
Saplings per sq.m
Stocking Index
Plot Panel Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5
190 3 0.08 0.08 0.08 0.08 - 0.07 0.08 0.06 0.05 - 2.14 1.01 1.01 1.01 -
191 3 0.50 0.08 0.33 0.33 - 0.05 0.05 0.02 0.01 - 89.35 23.25 5.28 5.28 -
192 3 0.92 0.67 0.58 1.83 - 0.05 0.04 0.04 0.04 - 33.68 17.84 7.29 29.28 -
193 3 1.08 1.00 0.75 0.33 - 0.29 0.31 0.20 0.20 - 97.01 87.71 49.64 35.94 -
194 3 1.08 1.08 0.58 0.42 - 0.18 0.13 0.09 0.07 - 57.93 62.08 45.24 66.10 -
195 3 0.00 0.08 0.42 0.33 - 0.12 0.09 0.09 0.11 - 22.24 43.23 55.79 63.21 -
196 3 0.25 0.25 0.17 0.17 - 0.26 0.17 0.15 0.14 - 34.81 31.54 44.23 40.21 -
198 3 2.08 2.50 2.42 2.92 - 0.17 0.11 0.11 0.07 - 81.93 96.38 42.98 71.25 -
269 4 0.08 0.00 0.17 0.17 - 0.15 0.12 0.09 0.06 - 31.67 22.24 17.97 9.55 -
270 4 0.42 0.33 0.17 0.17 - 0.22 0.19 0.14 0.11 - 111.59 41.22 17.97 2.14 -
271 4 0.25 0.25 0.58 0.33 - 0.09 0.08 0.07 0.07 - 18.98 12.69 67.10 13.70 -
296 4 1.17 0.83 0.08 0.42 - 0.02 0.01 0.00 0.00 - 90.10 66.98 1.01 7.29 -
297 4 0.17 0.33 0.33 1.00 - 0.06 0.05 0.05 0.04 - 16.96 12.69 11.56 14.70 -
298 4 0.08 0.08 0.00 0.25 - 0.04 0.02 0.02 0.02 - 8.42 1.01 0.00 3.14 -
299 4 0.33 0.33 0.33 0.67 - 0.05 0.05 0.04 0.04 - 83.82 107.82 5.28 10.43 -
300 4 0.08 0.08 0.08 0.00 - 0.02 0.02 0.02 0.02 - 8.42 2.14 2.14 0.00 -
301 4 3.92 6.92 13.33 12.50 - 0.04 0.04 0.04 0.02 - 49.26 104.68 226.19 266.03 -
302 4 0.25 0.25 0.25 0.17 - 0.33 0.21 0.18 0.11 - 64.47 28.53 12.69 4.15 -
305 4 0.00 0.17 0.08 0.25 - 0.15 0.15 0.11 0.11 - 44.48 55.04 31.67 33.80 -
308 4 1.42 1.33 2.25 2.42 - 0.12 0.11 0.12 0.13 - 59.82 114.35 115.48 181.58 -
313 4 0.25 0.08 0.00 0.00 - 0.04 0.02 0.02 0.02 - 4.15 1.01 0.00 0.00 -
369 3 - 0.75 0.25 0.67 - - 0.07 0.06 0.04 - - 19.98 5.28 10.43 -


Table 2. Average % cover and number of invasive species detected in each plot by cycle. Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Plots are sampled in 4-year rotations, with a quarter of the plots sampled each year (i.e. a panel). Note that cycle 5 is only partially complete. Plots with at least 10% average cover or 4 or more invasive species present are in yellow. Average cover and species counts may be increasing over time due to protocol changes, including additions to the indicator species list over time, a plot search for indicator species starting in 2009 and all woody species being sampled in quadrats starting in 2019. More details can be found in the MIDN Summary of Major Protocol Changes

table output
Average % Cover
Number of Species per Plot
PlotCode PanelCode Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5
21 1 57.79 53.48 47.61 42.12 37.52 2 3 3 4 4
22 1 44.00 46.93 42.38 62.38 46.92 2 3 4 5 4
23 1 0.00 0.00 0.00 0.00 0.00 0 1 0 0 0
24 1 1.46 15.01 24.93 54.59 31.27 2 2 1 2 2
25 1 0.00 0.01 3.75 4.61 1.26 0 1 1 2 1
26 1 0.00 0.00 0.00 0.00 0.00 0 0 0 1 2
27 1 0.14 0.31 11.47 7.58 24.59 2 2 2 2 2
65 1 0.00 0.00 0.00 0.00 0.00 0 0 0 0 0
66 1 0.00 0.00 0.00 0.00 0.00 0 0 0 0 0
67 1 0.00 0.00 0.00 0.00 0.00 0 0 0 0 0
68 1 0.00 0.00 0.00 0.00 0.01 0 0 0 0 1
69 1 0.00 0.01 0.00 0.00 0.00 0 1 0 0 0
70 1 0.00 0.00 0.00 0.00 0.00 0 0 0 0 0
103 2 0.00 0.00 0.00 0.00 - 0 0 0 0 -
104 2 0.00 0.00 0.00 0.00 - 0 0 0 0 -
105 2 0.00 0.00 0.00 0.00 - 0 0 0 0 -
109 2 0.00 0.00 0.00 0.00 - 0 0 0 0 -
110 2 0.00 0.00 0.00 0.00 - 0 0 0 0 -
111 2 0.02 0.13 0.30 0.30 - 1 1 1 1 -
135 2 0.00 0.01 0.00 0.00 - 0 1 1 1 -
136 2 2.50 4.18 6.47 3.36 - 1 2 2 2 -
137 2 0.02 0.13 1.76 3.88 - 1 1 1 1 -
138 2 1.38 66.74 48.13 41.38 - 2 3 3 3 -
139 2 0.02 0.05 0.03 3.28 - 1 2 3 5 -
140 2 0.00 0.01 0.01 0.13 - 0 1 3 3 -
141 2 1.41 27.64 31.89 36.62 - 2 3 4 4 -
172 3 0.00 0.01 0.26 0.27 - 2 2 1 1 -
186 3 0.00 0.00 0.00 0.00 - 0 0 1 1 -
188 3 0.00 0.00 0.00 0.00 - 0 0 0 0 -
189 3 0.62 33.49 43.82 66.89 - 2 4 3 4 -



Table 2 (cont.). Average % cover and number of invasive species detected in each plot by cycle. Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Plots are sampled in 4-year rotations, with a quarter of the plots sampled each year (i.e. a panel). Note that cycle 5 is only partially complete. Plots with at least 10% average cover or 4 or more invasive species present are in yellow. Average cover and species counts may be increasing over time due to protocol changes, including additions to the indicator species list over time, a plot search for indicator species starting in 2009 and all woody species being sampled in quadrats starting in 2019. More details can be found in the MIDN Summary of Major Protocol Changes

table output
Average % Cover
Number of Species per Plot
PlotCode PanelCode Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5 Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5
190 3 22.33 29.02 31.63 47.27 - 2 3 3 3 -
191 3 0.05 1.78 0.06 0.58 - 2 2 2 2 -
192 3 0.95 5.38 1.92 0.58 - 2 2 2 2 -
193 3 0.00 0.00 0.00 0.00 - 0 0 1 0 -
194 3 0.01 0.01 0.00 0.00 - 1 1 0 0 -
195 3 0.00 0.00 0.00 0.00 - 0 1 1 0 -
196 3 0.00 0.00 0.00 0.00 - 0 0 0 0 -
198 3 0.00 0.00 0.00 0.01 - 0 1 1 3 -
269 4 0.00 0.00 0.00 0.00 - 0 0 0 0 -
270 4 0.00 0.00 0.00 0.00 - 0 0 0 0 -
271 4 0.00 0.00 0.00 0.00 - 0 0 0 0 -
296 4 3.25 6.82 1.63 0.40 - 2 2 3 2 -
297 4 0.03 0.02 0.03 4.03 - 2 2 2 3 -
298 4 14.39 31.42 9.18 5.98 - 2 2 3 5 -
299 4 0.01 0.03 0.03 1.08 - 2 2 2 2 -
300 4 0.00 0.00 0.00 0.00 - 0 0 0 1 -
301 4 0.00 2.16 7.80 3.68 - 0 2 1 2 -
302 4 0.00 0.00 0.00 0.00 - 1 1 1 1 -
305 4 0.00 0.00 0.00 0.00 - 0 0 0 0 -
308 4 0.00 0.02 0.01 0.00 - 1 1 1 2 -
313 4 0.00 0.00 0.00 0.00 - 0 1 0 0 -
369 3 - 22.88 11.91 9.62 - - 2 2 3 -





Table 3. Number of plots out of 52 where priority invasive species were detected. Cycle 1: 2007 – 2010; Cycle 2: 2011 – 2014; Cycle 3: 2015 – 2018; Cycle 4: 2019 – 2022; Cycle 5: 2023. Species on the list include all exotic vascular plant species that are capable of dominating Eastern US forest habitats, and does not include all exotic species detected in MIDN forest plots. Note that cycle 5 is only partially complete.Average cover and species counts may be increasing over time due to additions to the protocols, including a plot search for additional indicator species starting in 2009 and all woody species being sampled in quadrats starting in 2019. Species have also been added to the indicator list over time. More details can be found in the MIDN Summary of Major Protocol Changes

table output
Latin Name Common Name Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5
Ailanthus altissima Tree of heaven 1 0 1 3 0
Berberis thunbergii Japanese barberry 0 1 1 1 0
Celastrus orbiculatus oriental bittersweet 0 0 0 2 0
Euonymus fortunei climbing euonymus 1 0 0 0 0
Ligustrum privet 0 5 8 10 2
Lonicera - Exotic honeysuckle - exotic 4 0 0 0 0
Lonicera japonica Japanese honeysuckle 14 22 22 22 4
Microstegium vimineum Japanese stiltgrass 17 23 24 25 7
Persicaria longiseta Oriental lady's thumb 0 4 1 4 2
Rosa multiflora multiflora rose 0 3 1 4 1
Rubus phoenicolasius wine raspberry 0 0 1 2 0



Table 4. Invasive plant and pest/pathogen early detections in Petersburg National Battlefield observed in the most recent census of each plot. Coordinates are in UTM NAD83 Zone 18N.

table output
Plot Year X Y Latin Name Common Name Type
PETE-137 2021 290350 4122799 Microstegium vimineum Japanese stiltgrass graminoid
PETE-298 2022 290844 4122558 Microstegium vimineum Japanese stiltgrass graminoid
PETE-135 2021 291351 4123059 Microstegium vimineum Japanese stiltgrass graminoid
PETE-308 2022 291097 4123545 Microstegium vimineum Japanese stiltgrass graminoid
PETE-141 2021 288843 4121550 Microstegium vimineum Japanese stiltgrass graminoid
PETE-068 2023 267857 4113056 Microstegium vimineum Japanese stiltgrass graminoid
PETE-190 2021 289096 4122054 Microstegium vimineum Japanese stiltgrass graminoid
PETE-025 2023 290599 4122300 Microstegium vimineum Japanese stiltgrass graminoid
PETE-026 2023 291100 4123801 Microstegium vimineum Japanese stiltgrass graminoid
PETE-136 2021 291340 4122552 Microstegium vimineum Japanese stiltgrass graminoid
PETE-198 2021 281607 4116550 Microstegium vimineum Japanese stiltgrass graminoid
PETE-301 2022 289856 4122301 Microstegium vimineum Japanese stiltgrass graminoid
PETE-138 2021 291602 4123059 Microstegium vimineum Japanese stiltgrass graminoid
PETE-297 2022 291365 4123548 Microstegium vimineum Japanese stiltgrass graminoid
PETE-139 2021 290852 4124552 Microstegium vimineum Japanese stiltgrass graminoid
PETE-191 2021 290852 4123795 Microstegium vimineum Japanese stiltgrass graminoid
PETE-024 2023 290602 4122051 Microstegium vimineum Japanese stiltgrass graminoid
PETE-027 2023 291350 4124048 Microstegium vimineum Japanese stiltgrass graminoid
PETE-192 2021 291097 4122784 Microstegium vimineum Japanese stiltgrass graminoid
PETE-021 2023 290597 4123801 Microstegium vimineum Japanese stiltgrass graminoid
PETE-369 2021 290605 4123299 Microstegium vimineum Japanese stiltgrass graminoid
PETE-140 2021 289848 4122548 Microstegium vimineum Japanese stiltgrass graminoid
PETE-022 2023 289346 4121550 Microstegium vimineum Japanese stiltgrass graminoid
PETE-299 2022 290854 4122796 Microstegium vimineum Japanese stiltgrass graminoid
PETE-189 2021 289621 4122054 Microstegium vimineum Japanese stiltgrass graminoid
PETE-296 2022 291370 4123800 Microstegium vimineum Japanese stiltgrass graminoid
PETE-298 2022 290844 4122558 Celastrus orbiculatus oriental bittersweet shrub
PETE-369 2021 290605 4123299 Celastrus orbiculatus oriental bittersweet shrub
PETE-186 2021 290841 4122299 Rubus phoenicolasius wine raspberry shrub
PETE-139 2021 290852 4124552 Rubus phoenicolasius wine raspberry shrub